The present invention relates to methods to image the skin surface in order to view intercellular and intracellular structure. In particular, the invention relates to use of a compound (e.g., fluorescent dye) to enhance contrast and obtain better imaging.
Methods, especially in vivo methods, for imaging both the skin surface as well as deeper skin layers at a wide range of lateral resolutions are available. For example, in vivo confocal microscopy is capable of imaging skin at sufficient lateral and axial resolution and with sufficient contrast to distinguish individual skin cells below the skin surface (versus on the skin surface as disclosed by method of the subject invention).
In In vivo Confocal Scanning Laser Microscopy of Human Skin II: Advances in Instrumentation and Comparison With Histology, M. Rajadhyaksha et al. J. Invest. Dermatol. 113 (1999) 293, images are shown of various skin layers, from the skin surface to the dermis. Individual skin cells at the skin surface can be identified but the overall contrast at the surface is poor. Further, the confocal scanning technique is completely different than the dye technique of the subject invention in that it uses a completely different source of contrast.
As far as applicants are aware, a technique using a compound (e.g., a fluorescent dye) for imaging skin surface at the cellular level in vivo is unknown.
The present invention relates to a preferably in vivo method to image the intercellular and intracellular structure of the skin surface using a technique to enhance contrast.
The present invention is believed to represent a novel way for making such in vivo measurement.
In the embodiment of the present invention, the intercellular and intracellular structure of the skin surface is imaged by choosing a desired spot on the subject""s body; applying a desired amount of a contrast enhancing compound (e.g., fluorescent dye) to the site; taking a stack or multiplicity of images (e.g., fluorescence images) at different focal planes (for example 1 to 1000, preferably 1-100); and, if necessary, performing a maximum intensity rendering of the resulting stack of images.
More specifically, the invention comprises a method to image the intercellular and intracellular structure of the skin surface comprising:
1. choosing a desired site, typically circular, with a diameter of 0.5xe2x80x3, although it should be understood that the site can be larger or smaller or differently shaped, on the body of a subject;
2. applying a contrast-enhancing compound to the chosen area; in principal such compound can be any compound which absorbs heterogeneously at the skin surface and can be detected by appropriate imaging tool; typically this would be a fluorescent dye;
3. acquiring a stack or multiplicity of images (typically multiple fluorescent images) of an area, typically 0.01xc3x970.01xe2x80x3 in size but the area can be either smaller or larger, varying the focal plane over a range from just above the highest point to just below the lowest point of the surface area that is imaged, typically in steps of 2 xcexcm, although the step size can be smaller or larger;
4. reconstructing the resulting multiple images into a single image that shows all the cells at the skin surface in focus (or, if a single image is possible, such reconstruction of multiple images is not necessary), regardless of any skin texture, by performing a maximum intensity rendering of the stack of images; and
5. if desired, repeating steps 3 and 4 to obtain additional images within the chosen body site.